Manufacture of rubber thread



Jan. 16, 1934. E. HOPKINSON MANUFACTURE OF RUBBER THREAD Filed May 9, 1951 INVENTOR 67/ /57 HUP/f/MMA/ Patented Jan. 16, 1934 UNITED STATES MANUFACTURE or RUBBER THREAD Ernest Hopkinson, New York, N. Y., assignor to National India Rubber Company, Providence, R. L, a corporation of Rhode Island Application May 9, 1931, Serial No. 536,195 Renewed December 3, 1932 4 Claims.

This invention relates to a process for'the manufacture of rubber-thread and has for an object the continuous and rapid production of such thread in'an easy andinexpensive manner from any suitable rubber-containing fluid, preferably as aqueous dispersions of rubber, such as latex either natural or artificial.

Other objects and advantages of the invention will appear as the description proceeds, referw ence being made to the accompanying drawing in which- Figure 1 is an elevation partly in section of apparatus suitable for carrying out the invention;

Fig. 2 is a plan view of Fig. 1; and i Fig. 3 is a sectional view of one of the parts included in the apparatus.

The invention may be embodied in various ways. For instance, there may be provided a drum having a substantially flat surface and which is continuously rotated in the direction of the arrow 11 by any suitable driving means such as a belt and pulley 12. A roller 13 rotating in contact with the drum 10 and dipping into a bath of suitable rubber-containing fluid 14, preferably latex, is adapted to lay the rubber fluid upon the drum 10 to form a strip S. The rubber-containing fluid 14 is preferably of a nature to be acted upon by a suitable accelerator to speed vul-' canization of the advancing strip of rubber. For carrying out this. purpose there may be provided a' second'roller 15 which dips into a solution of an accelerating medium 16, the roller being in contact with the strip S on the drum so that the accelerator is constantly applied to the strip as the drum rotates. After application of the accelerator, the strip S is preferably subjected to heat treatment by means of a heater 1'! to dry or iii partially dry the strip and is thereafter removed from the drum 10. At the point where the strip S leaves the drum 10, an air blast maybe used to facilitate removalof the strip. The apparatus is properly regulated by controlling the heating means 17 so that the strip may be removed from the drum before complete vulcanization, and,

tating forming devices 18 having channel-shaped annular grooves 19 which fold or consolidate the folded strip between a roller 20 and a traveling preferably, is then carried through a pair of ro-' belt 21, the belt being moved rapidly to and fro transversely to the direction in which the rubber strip S is traveling over the drum 20, so that the rubber is constantly rolled on itself into a substantially round thread. From the rolling de- 80 vice the thread may be carried over a guide roller 22 and then onto the surface of a rotating drum 23, where it is heated by any suitable means such as a heater 24 adapted to vulcanize the thread, and then maybe wound upon a reel 25 or other-= wise accumulated. I For operating the rolling device, the belt 21 may be mounted upon a pair of rollers 26 carried upon shafts 27 which are moved by a cross bar 28 driven by suitable means such as a crank 29 Z0 and a connecting link 30. The strip S preferably is maintained under a slight pull between the rolling device and the drum 10 so as to insure entry of the strip into the grooves 19. This may be done by adjusting the speed of the roller 20 with relation to that of the drum 10.

It is to be understood thatthe above described embodiment is merely illustrative of one practical form of apparatus for carrying out the invention which is capable of being otherwise embodied in various ways within the scope of the appended claims. The invention embraces the steps of forming a thin strip from a suitable rubber-containing fluid upon an advancing surface adapted to dry or partially dry. the strip, folding the strip transversely of its length and then rolling the folded strip into a substantially round thread, after which complete vulcanization may be effected. The ingredients of the rubber-containing fluid may bechanged as desired. Rubber latex has been found'to possess the most desirable characteristics for the production of rubber thread, and in some cases artificial dispersions of rubber may be suitable. The latex bath 14 may contain only latex, and the accelerator bath 16 may contain a mixture of curing and accelerating agents, or a single bath may be employed contai'i'iing all the ingredients necessary to the finished thread, which would ordinarily include a curing ingredient, such as sulphur, and any desired accelerating agents. As a further example, the latex bathmay contain latex and a curing agent, and the accelerator bath contain only an accelerator. Also vulcanized latex may be used in carrying out this process, in which case the accelerator is dispensed with and the drum 10 with its heater 1'! acts as a drying means to put the rubber strip into suitable condition prior to forming the same into substantially round crosssection by rolling. The other drum 23 may then complete the drying operation by proper regulation of the heater 24.

Having thus described my invention what I claim and desire to protect by Lelters Patent is:

1. The method of manufacturing elastic thread which comprises forming a strip from an aque-' ous dispersion of rubber, folding the strip transversely, and rolling the folded strip to form a substantially round thread.

2. The method of manufacturing elastic thread which comprises forming a strip from an aqueous dispersion of rubber, folding said strip transversely, rolling the folded strip alternately in op- 4. The method of manufacturing elastic. thread, which comprises continuously forming a strip from an aqueous dispersion of rubber, and

rolling the strip alternately in opposite directions transversely of itslength to form a substantially round thread. ERNEST HOPKINSON. 

